1. Field of the Invention
This invention is related to a pair of eyeglasses and in particular to eyeglasses which can be adjusted to change the focus.
2. Description of the Prior Art
Although the eye is a marvelously sophisticated device, it does not always work perfectly. If the eyeball is slightly too large or too small, for example, the lens cannot focus properly on the retina. Just like a magnifying glass, the lens focuses light onto the retina, the film of sensitive cells on the back of the eyeball. If the light comes from a nearby object, making it difficult to focus, the muscles around the lens can squeeze it into a different shape, allowing it to bend or refract the light properly. This process is called accommodation. As the human eye ages, the lens becomes stiffer and harder to accommodate. For this type of faulty vision, the solution is a pair of eyeglasses. However, the conventional eyeglasses cannot be adjusted to change the focus thereby making it necessary for one who can see and read things clearly only at different focuses to prepare two or more pairs of eyeglasses in order to adapt to various conditions.
Therefore, it is an object of the present invention to provide a pair of eyeglasses which can be adjusted to change the focus as desired.